Today there is a great emphasis on conserving water and water related heat energy. Shower heads and faucets may be designed to restrict flow to a maximum flow rate. The toilet may also be designed to use no more than 1.6 gallons per flush. And the temperature of the water outputted by the hot water heating device is being set at lower and lower temperatures.
U.S. patent application Ser. No. 08/972,848 filed Nov. 18, 1997, discloses a system wherein each pipe, which discharges water in an apartment, etc., has a monitor attached thereto to determine the flow of the pipe and the temperature of the water flowing through the pipe. With this information the total volume of water used in the unit and the heat energy added to the water can be calculated. U.S. patent application Ser. No. 08/972,848 discloses a monitor for such application. These applications are incorporated by reference herein.